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1.
Life Sci Alliance ; 7(8)2024 Aug.
Article in English | MEDLINE | ID: mdl-38839106

ABSTRACT

Targeted therapies against mutant BRAF are effectively used in combination with MEK inhibitors (MEKi) to treat advanced melanoma. However, treatment success is affected by resistance and adverse events (AEs). Approved BRAF inhibitors (BRAFi) show high levels of target promiscuity, which can contribute to these effects. The blood vessel lining is in direct contact with high plasma concentrations of BRAFi, but effects of the inhibitors in this cell type are unknown. Hence, we aimed to characterize responses to approved BRAFi for melanoma in the vascular endothelium. We showed that clinically approved BRAFi induced a paradoxical activation of endothelial MAPK signaling. Moreover, phosphoproteomics revealed distinct sets of off-targets per inhibitor. Endothelial barrier function and junction integrity were impaired upon treatment with vemurafenib and the next-generation dimerization inhibitor PLX8394, but not with dabrafenib or encorafenib. Together, these findings provide insights into the surprisingly distinct side effects of BRAFi on endothelial signaling and functionality. Better understanding of off-target effects could help to identify molecular mechanisms behind AEs and guide the continued development of therapies for BRAF-mutant melanoma.


Subject(s)
Melanoma , Protein Kinase Inhibitors , Proto-Oncogene Proteins B-raf , Signal Transduction , Vemurafenib , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Proto-Oncogene Proteins B-raf/metabolism , Humans , Protein Kinase Inhibitors/pharmacology , Melanoma/drug therapy , Melanoma/metabolism , Signal Transduction/drug effects , Vemurafenib/pharmacology , Oximes/pharmacology , Sulfonamides/pharmacology , Endothelium, Vascular/drug effects , Endothelium, Vascular/metabolism , Imidazoles/pharmacology , Endothelial Cells/drug effects , Endothelial Cells/metabolism , MAP Kinase Signaling System/drug effects , Carbamates/pharmacology , Human Umbilical Vein Endothelial Cells/drug effects , Human Umbilical Vein Endothelial Cells/metabolism , Cell Line, Tumor , Mutation
2.
Int J Mol Sci ; 25(10)2024 May 19.
Article in English | MEDLINE | ID: mdl-38791574

ABSTRACT

Being a component of the Ras/Raf/MEK/ERK signaling pathway crucial for cellular responses, the VRAF murine sarcoma viral oncogene homologue B1 (BRAF) kinase has emerged as a promising target for anticancer drug discovery due to oncogenic mutations that lead to pathway hyperactivation. Despite the discovery of several small-molecule BRAF kinase inhibitors targeting oncogenic mutants, their clinical utility has been limited by challenges such as off-target effects and suboptimal pharmacological properties. This study focuses on identifying miniprotein inhibitors for the oncogenic V600E mutant BRAF, leveraging their potential as versatile drug candidates. Using a structure-based de novo design approach based on binding affinity to V600E mutant BRAF and hydration energy, 39 candidate miniprotein inhibitors comprising three helices and 69 amino acids were generated from the substructure of the endogenous ligand protein (14-3-3). Through in vitro binding and kinase inhibition assays, two miniproteins (63 and 76) were discovered as novel inhibitors of V600E mutant BRAF with low-micromolar activity, with miniprotein 76 demonstrating a specific impediment to MEK1 phosphorylation in mammalian cells. These findings highlight miniprotein 76 as a potential lead compound for developing new cancer therapeutics, and the structural features contributing to its biochemical potency against V600E mutant BRAF are discussed in detail.


Subject(s)
Protein Kinase Inhibitors , Proto-Oncogene Proteins B-raf , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Proto-Oncogene Proteins B-raf/genetics , Proto-Oncogene Proteins B-raf/metabolism , Humans , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/chemistry , Mutation , Drug Discovery/methods , Phosphorylation/drug effects , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Drug Design , Protein Binding , Structure-Activity Relationship , Models, Molecular
3.
Expert Rev Hematol ; 17(6): 223-231, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38721670

ABSTRACT

INTRODUCTION: Langerhans cell histiocytosis (LCH) is a rare myeloid neoplasm, encompassing a diverse clinical spectrum ranging from localized bone or skin lesions to a multisystemic life-threatening condition. Over the past decade, there has been an expansion in understanding the molecular biology of LCH, which translated into innovative targeted therapeutic approaches. AREAS COVERED: In this article, we will review the molecular alterations observed in pediatric LCH and the relationship between these molecular changes and the clinical phenotype, as well as targeted therapies in LCH. EXPERT OPINION: Mitogen-activated protein kinase (MAPK) pathway mutation is a hallmark of LCH and is identified in 80% of the cases. Notably, BRAFV600E mutation is seen in ~50-60% of the cases, ~30% has other MAPK pathway mutations, while 15-20% have no detected mutations. While the first line therapeutic approach is vinblastine and prednisone, targeted therapies - specifically BRAF/MEK inhibitors - emerged as a promising second-line salvage strategy, particularly when a mutation is identified. Most patients respond to BRAF/MEK inhibitors but at least 75% reactivate after stopping, however, most patients respond again when restarting inhibitors.


Subject(s)
Histiocytosis, Langerhans-Cell , Molecular Targeted Therapy , Humans , Child , Histiocytosis, Langerhans-Cell/genetics , Histiocytosis, Langerhans-Cell/drug therapy , Histiocytosis, Langerhans-Cell/therapy , Histiocytosis, Langerhans-Cell/diagnosis , Mutation , Proto-Oncogene Proteins B-raf/genetics , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Genetic Markers , Protein Kinase Inhibitors/therapeutic use , MAP Kinase Signaling System/drug effects
4.
Elife ; 132024 May 14.
Article in English | MEDLINE | ID: mdl-38742856

ABSTRACT

The type II class of RAF inhibitors currently in clinical trials paradoxically activate BRAF at subsaturating concentrations. Activation is mediated by induction of BRAF dimers, but why activation rather than inhibition occurs remains unclear. Using biophysical methods tracking BRAF dimerization and conformation, we built an allosteric model of inhibitor-induced dimerization that resolves the allosteric contributions of inhibitor binding to the two active sites of the dimer, revealing key differences between type I and type II RAF inhibitors. For type II inhibitors the allosteric coupling between inhibitor binding and BRAF dimerization is distributed asymmetrically across the two dimer binding sites, with binding to the first site dominating the allostery. This asymmetry results in efficient and selective induction of dimers with one inhibited and one catalytically active subunit. Our allosteric models quantitatively account for paradoxical activation data measured for 11 RAF inhibitors. Unlike type II inhibitors, type I inhibitors lack allosteric asymmetry and do not activate BRAF homodimers. Finally, NMR data reveal that BRAF homodimers are dynamically asymmetric with only one of the subunits locked in the active αC-in state. This provides a structural mechanism for how binding of only a single αC-in inhibitor molecule can induce potent BRAF dimerization and activation.


Subject(s)
Protein Kinase Inhibitors , Protein Multimerization , Proto-Oncogene Proteins B-raf , Proto-Oncogene Proteins B-raf/metabolism , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Proto-Oncogene Proteins B-raf/chemistry , Allosteric Regulation/drug effects , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/metabolism , Protein Multimerization/drug effects , Humans , Protein Conformation , Protein Binding , Models, Molecular
5.
Life Sci ; 348: 122692, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38710283

ABSTRACT

Erdheim Chester Disease (ECD) is a rare histiocytic disorder marked by infiltration of organs with CD68+ histiocytes. ECD stems from mutations of BRAF and MAP2K1 in hematopoietic stem and progenitor cells (HSPCs), which further differentiate into monocytes and histiocytes. Histopathology reveals lipid-containing histiocytes, which test positive for CD68 and CD133 in immunohistochemistry. Signs and symptoms vary and depend on the organ/s of manifestation. Definitive radiological results associated with ECD include hairy kidney, coated aorta, and cardiac pseudotumor. Treatment options primarily include anti-cytokine therapy and inhibitors of BRAF and MEK signaling.


Subject(s)
Erdheim-Chester Disease , Erdheim-Chester Disease/drug therapy , Erdheim-Chester Disease/diagnosis , Erdheim-Chester Disease/genetics , Erdheim-Chester Disease/therapy , Erdheim-Chester Disease/pathology , Erdheim-Chester Disease/metabolism , Humans , Proto-Oncogene Proteins B-raf/genetics , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Histiocytes/pathology , Histiocytes/metabolism
6.
Lakartidningen ; 1212024 Feb 27.
Article in Swedish | MEDLINE | ID: mdl-38712675

ABSTRACT

Anaplastic and poorly differentiated thyroid cancer (ATC, PDTC) are rare and highly aggressive tumors that historically have been associated with a short life expectancy and low chance of cure. Molecular pathology and the introduction of highly effective targeted drugs have revolutionized the possibilities of management of patients with ATC and PDTC, with BRAF and MEK inhibitors as the most prominent example. Here we provide updated recommendations regarding diagnostics and management, including primary surgical management and targeted therapies based on specific molecular pathological findings.


Subject(s)
Molecular Targeted Therapy , Proto-Oncogene Proteins B-raf , Thyroid Carcinoma, Anaplastic , Thyroid Neoplasms , Humans , Thyroid Neoplasms/pathology , Thyroid Neoplasms/drug therapy , Thyroid Neoplasms/genetics , Thyroid Neoplasms/diagnosis , Proto-Oncogene Proteins B-raf/genetics , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Thyroid Carcinoma, Anaplastic/drug therapy , Thyroid Carcinoma, Anaplastic/pathology , Thyroid Carcinoma, Anaplastic/genetics , Thyroid Carcinoma, Anaplastic/diagnosis , Protein Kinase Inhibitors/therapeutic use , Antineoplastic Agents/therapeutic use
8.
Anticancer Res ; 44(6): 2349-2358, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38821628

ABSTRACT

BACKGROUND/AIM: Approximately 50% of melanomas harbor the BRAF V600E mutation and targeted therapies using BRAF inhibitors improve patient outcomes. Nonetheless, resistance to BRAF inhibitors develops rapidly and remains a challenge in melanoma treatment. In this study, we attempted to isolate long noncoding RNAs (lncRNAs) involved in BRAF inhibitor resistance using a comprehensive screening method. MATERIALS AND METHODS: We used a CRISPR-Cas9 synergistic activation mediator (SAM) protein complex in a genome-scale transcriptional activation assay to screen for candidate lncRNA genes related to BRAF inhibitor resistance. Correlation analysis was performed between expression levels of isolated lncRNA genes and IC50 of dabrafenib in a BRAF-mutated melanoma cell line. Next, online databases were used to construct the lncRNA-miRNA-mRNA regulatory network. Finally, we evaluated the significance of the expression levels of these lncRNAs and mRNAs as biomarkers using clinical specimens. RESULTS: We isolated three BRAF inhibitor resistance-associated lncRNA genes, namely SNHG16, NDUFV2-AS1, and LINC01502. We constructed a lncRNA-miRNA-mRNA network of 13 nodes consisting of three lncRNAs, six miRNAs, and four mRNAs. The lncRNAs and target mRNAs from each regulatory axis significantly and positively correlated with each other. Finally, Kaplan-Meier analysis showed that higher expression levels of MITF, which was up-regulated by LINC01502, were significantly associated with worse prognosis in BRAF V600E-mutated melanoma. CONCLUSION: The identification of these BRAF inhibitor resistance-associated lncRNA genes at the genomic scale and the establishment of the lncRNA-miRNA-mRNA regulatory network provides new insights into the underlying mechanisms of BRAF inhibitor resistance in melanoma.


Subject(s)
CRISPR-Cas Systems , Drug Resistance, Neoplasm , Melanoma , Protein Kinase Inhibitors , Proto-Oncogene Proteins B-raf , RNA, Long Noncoding , Transcriptional Activation , Humans , Proto-Oncogene Proteins B-raf/genetics , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , RNA, Long Noncoding/genetics , Drug Resistance, Neoplasm/genetics , Melanoma/genetics , Melanoma/drug therapy , Melanoma/pathology , Cell Line, Tumor , Protein Kinase Inhibitors/pharmacology , Gene Expression Regulation, Neoplastic/drug effects , Imidazoles/pharmacology , Mutation , Oximes/pharmacology , RNA, Messenger/genetics , Gene Regulatory Networks
9.
Cell Mol Life Sci ; 81(1): 238, 2024 May 25.
Article in English | MEDLINE | ID: mdl-38795180

ABSTRACT

BRAFV600E represents a constitutively active onco-kinase and stands as the most prevalent genetic alteration in thyroid cancer. However, the clinical efficacy of small-molecule inhibitors targeting BRAFV600E is often limited by acquired resistance. Here, we find that nerve/glial antigen 2 (NG2), also known as chondroitin sulfate proteoglycan 4 (CSPG4), is up-regulated in thyroid cancers, and its expression is increased with tumor progression in a BRAFV600E-driven thyroid cancer mouse model. Functional studies show that NG2 knockout almost does not affect tumor growth, but significantly improves the response of BRAF-mutant thyroid cancer cells to BRAF inhibitor PLX4720. Mechanistically, the blockade of ERK-dependent feedback by BRAF inhibitor can activate receptor tyrosine kinase (RTK) signaling, causing the resistance to this inhibitor. NG2 knockout attenuates the PLX4720-mediated feedback activation of several RTKs, improving the sensitivity of BRAF-mutant thyroid cancer cells to this inhibitor. Based on this finding, we propose and demonstrate an alternative strategy for targeting NG2 to effectively treat BRAF-mutant thyroid cancers by combining multiple kinase inhibitor (MKI) Sorafenib or Lenvatinib with PLX4720. Thus, this study uncovers a new mechanism in which NG2 contributes to the resistance of BRAF-mutant thyroid cancer cells to BRAF inhibitor, and provides a promising therapeutic option for BRAF-mutant thyroid cancers.


Subject(s)
Drug Resistance, Neoplasm , Indoles , Protein Kinase Inhibitors , Proto-Oncogene Proteins B-raf , Sulfonamides , Thyroid Neoplasms , Proto-Oncogene Proteins B-raf/genetics , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Proto-Oncogene Proteins B-raf/metabolism , Humans , Animals , Thyroid Neoplasms/drug therapy , Thyroid Neoplasms/genetics , Thyroid Neoplasms/pathology , Thyroid Neoplasms/metabolism , Indoles/pharmacology , Mice , Drug Resistance, Neoplasm/drug effects , Drug Resistance, Neoplasm/genetics , Sulfonamides/pharmacology , Protein Kinase Inhibitors/pharmacology , Cell Line, Tumor , Phenylurea Compounds/pharmacology , Phenylurea Compounds/therapeutic use , Sorafenib/pharmacology , Quinolines/pharmacology , Mutation , Antigens/metabolism , Proteoglycans/metabolism , Membrane Proteins , Chondroitin Sulfate Proteoglycans
10.
Cell Commun Signal ; 22(1): 282, 2024 May 22.
Article in English | MEDLINE | ID: mdl-38778340

ABSTRACT

Extracellular vesicles (EVs) constitute a vital component of intercellular communication, exerting significant influence on metastasis formation and drug resistance mechanisms. Malignant melanoma (MM) is one of the deadliest forms of skin cancers, because of its high metastatic potential and often acquired resistance to oncotherapies. The prevalence of BRAF mutations in MM underscores the importance of BRAF-targeted therapies, such as vemurafenib and dabrafenib, alone or in combination with the MEK inhibitor, trametinib. This study aimed to elucidate the involvement of EVs in MM progression and ascertain whether EV-mediated metastasis promotion persists during single agent BRAF (vemurafenib, dabrafenib), or MEK (trametinib) and combined BRAF/MEK (dabrafenib/trametinib) inhibition.Using five pairs of syngeneic melanoma cell lines, we assessed the impact of EVs - isolated from their respective supernatants - on melanoma cell proliferation and migration. Cell viability and spheroid growth assays were employed to evaluate proliferation, while migration was analyzed through mean squared displacement (MSD) and total traveled distance (TTD) measurements derived from video microscopy and single-cell tracking.Our results indicate that while EV treatments had remarkable promoting effect on cell migration, they exerted only a modest effect on cell proliferation and spheroid growth. Notably, EVs demonstrated the ability to mitigate the inhibitory effects of BRAF inhibitors, albeit they were ineffective against a MEK inhibitor and the combination of BRAF/MEK inhibitors. In summary, our findings contribute to the understanding of the intricate role played by EVs in tumor progression, metastasis, and drug resistance in MM.


Subject(s)
Cell Movement , Extracellular Vesicles , Melanoma , Protein Kinase Inhibitors , Proto-Oncogene Proteins B-raf , Melanoma/pathology , Melanoma/drug therapy , Melanoma/metabolism , Extracellular Vesicles/metabolism , Proto-Oncogene Proteins B-raf/metabolism , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Proto-Oncogene Proteins B-raf/genetics , Humans , Cell Movement/drug effects , Cell Line, Tumor , Protein Kinase Inhibitors/pharmacology , Cell Proliferation/drug effects , Vemurafenib/pharmacology , Pyrimidinones/pharmacology , Pyridones/pharmacology , Pyridones/therapeutic use , Imidazoles/pharmacology , Oximes/pharmacology
11.
BMJ Case Rep ; 17(5)2024 May 08.
Article in English | MEDLINE | ID: mdl-38719253

ABSTRACT

The combination therapy of v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) and mitogen-activated protein kinase kinase (MEK) inhibitors is approved for treating patients with BRAF V600E-positive tumours, including melanoma and lung cancer. Several case reports indicated autoimmune side effects associated with the use of BRAF and MEK inhibitors. Still, the effects of these drugs on the immune system were not fully elucidated. Here, we report a patient with large-vessel vasculitis diagnosed after initiation of treatment with dabrafenib and trametinib for BRAF V600E-positive metastatic lung adenocarcinoma. She was a never-smoker woman in her early 70s who presented with a chronic cough and was diagnosed with BRAF V600E-positive metastatic lung adenocarcinoma by transbronchial lung biopsy. She was successfully treated with prednisolone and methotrexate while BRAF and MEK inhibitors were continued. We should be careful about autoimmune diseases using BRAF and MEK inhibitors.


Subject(s)
Adenocarcinoma of Lung , Imidazoles , Lung Neoplasms , Oximes , Protein Kinase Inhibitors , Proto-Oncogene Proteins B-raf , Pyridones , Pyrimidinones , Vasculitis , Humans , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Proto-Oncogene Proteins B-raf/genetics , Female , Pyridones/adverse effects , Pyridones/therapeutic use , Pyrimidinones/therapeutic use , Pyrimidinones/adverse effects , Lung Neoplasms/drug therapy , Aged , Adenocarcinoma of Lung/drug therapy , Imidazoles/adverse effects , Imidazoles/therapeutic use , Oximes/adverse effects , Oximes/therapeutic use , Vasculitis/chemically induced , Protein Kinase Inhibitors/adverse effects , Protein Kinase Inhibitors/therapeutic use , Prednisolone/therapeutic use , Methotrexate/therapeutic use , Methotrexate/adverse effects , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/therapeutic use
12.
Sci Signal ; 17(836): eadd5073, 2024 May 14.
Article in English | MEDLINE | ID: mdl-38743809

ABSTRACT

The Ras-mitogen-activated protein kinase (MAPK) pathway is a major target for cancer treatment. To better understand the genetic pathways that modulate cancer cell sensitivity to MAPK pathway inhibitors, we performed a CRISPR knockout screen with MAPK pathway inhibitors on a colorectal cancer (CRC) cell line carrying mutant KRAS. Genetic deletion of the catalytic subunit of protein phosphatase 6 (PP6), encoded by PPP6C, rendered KRAS- and BRAF-mutant CRC and BRAF-mutant melanoma cells more resistant to these inhibitors. In the absence of MAPK pathway inhibition, PPP6C deletion in CRC cells decreased cell proliferation in two-dimensional (2D) adherent cultures but accelerated the growth of tumor spheroids in 3D culture and tumor xenografts in vivo. PPP6C deletion enhanced the activation of nuclear factor κB (NF-κB) signaling in CRC and melanoma cells and circumvented the cell cycle arrest and decreased cyclin D1 abundance induced by MAPK pathway blockade in CRC cells. Inhibiting NF-κB activity by genetic and pharmacological means restored the sensitivity of PPP6C-deficient cells to MAPK pathway inhibition in CRC and melanoma cells in vitro and in CRC cells in vivo. Furthermore, a R264 point mutation in PPP6C conferred loss of function in CRC cells, phenocopying the enhanced NF-κB activation and resistance to MAPK pathway inhibition observed for PPP6C deletion. These findings demonstrate that PP6 constrains the growth of KRAS- and BRAF-mutant cancer cells, implicates the PP6-NF-κB axis as a modulator of MAPK pathway output, and presents a rationale for cotargeting the NF-κB pathway in PPP6C-mutant cancer cells.


Subject(s)
MAP Kinase Signaling System , NF-kappa B , Proto-Oncogene Proteins B-raf , Proto-Oncogene Proteins p21(ras) , Humans , Proto-Oncogene Proteins B-raf/genetics , Proto-Oncogene Proteins B-raf/metabolism , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , NF-kappa B/metabolism , NF-kappa B/genetics , Proto-Oncogene Proteins p21(ras)/genetics , Proto-Oncogene Proteins p21(ras)/metabolism , MAP Kinase Signaling System/drug effects , Animals , Cell Line, Tumor , Mutation , Mice , Protein Kinase Inhibitors/pharmacology , Cell Proliferation/drug effects , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/pathology , Melanoma/genetics , Melanoma/metabolism , Melanoma/drug therapy , Melanoma/pathology , Xenograft Model Antitumor Assays , Drug Resistance, Neoplasm/genetics , Drug Resistance, Neoplasm/drug effects , Mice, Nude
13.
Cell Rep ; 43(4): 114048, 2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38614086

ABSTRACT

Resistance to MAPK inhibitors (MAPKi), the main cause of relapse in BRAF-mutant melanoma, is associated with the production of alternative BRAF mRNA isoforms (altBRAFs) in up to 30% of patients receiving BRAF inhibitor monotherapy. These altBRAFs have been described as being generated by alternative pre-mRNA splicing, and splicing modulation has been proposed as a therapeutic strategy to overcome resistance. In contrast, we report that altBRAFs are generated through genomic deletions. Using different in vitro models of altBRAF-mediated melanoma resistance, we demonstrate the production of altBRAFs exclusively from the BRAF V600E allele, correlating with corresponding genomic deletions. Genomic deletions are also detected in tumor samples from melanoma and breast cancer patients expressing altBRAFs. Along with the identification of altBRAFs in BRAF wild-type and in MAPKi-naive melanoma samples, our results represent a major shift in our understanding of mechanisms leading to the generation of BRAF transcripts variants associated with resistance in melanoma.


Subject(s)
Drug Resistance, Neoplasm , Melanoma , Protein Kinase Inhibitors , Proto-Oncogene Proteins B-raf , Proto-Oncogene Proteins B-raf/genetics , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Proto-Oncogene Proteins B-raf/metabolism , Melanoma/genetics , Melanoma/drug therapy , Melanoma/pathology , Humans , Drug Resistance, Neoplasm/genetics , Protein Kinase Inhibitors/pharmacology , Cell Line, Tumor , Protein Isoforms/metabolism , Protein Isoforms/genetics , Alternative Splicing/genetics , Female , Gene Deletion
14.
J Cancer Res Ther ; 20(2): 570-577, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38687926

ABSTRACT

OBJECTIVE: This study aimed to investigate BVD-523 (ulixertinib), an adenosine triphosphate (ATP)-dependent extracellular signal-regulated kinases 1/2 inhibitor, for its antitumor potential in thyroid cancer. MATERIALS AND METHODS: Ten thyroid cancer cell lines known to carry mitogen-activated protein kinase (MAPK)-activated mutations, including v-Raf murine sarcoma viral oncogene homolog B (BRAF) and rat sarcoma virus (RAS) mutations, were examined. Cells were exposed to a 10-fold concentration gradient ranging from 0 to 3000 nM for 5 days. The half-inhibitory concentration was determined using the Cell Counting Kit-8 assay. Following BVD-523 treatment, cell cycle analysis was conducted using flow cytometry. In addition, the impact of BVD-523 on extracellular signal-regulated kinase (ERK)- dependent ribosomal S6 kinase (RSK) activation and the expression of cell cycle markers were assessed through western blot analysis. RESULTS: BVD-523 significantly inhibited thyroid cancer cell proliferation and induced G1/S cell cycle arrest dose-dependently. Notably, cell lines carrying MAPK mutations, especially those with the BRAF V600E mutation, exhibited heightened sensitivity to BVD-523's antitumor effects. Furthermore, BVD-523 suppressed cyclin D1 and phosphorylated retinoblastoma protein expression, and it robustly increased p27 levels in an RSK-independent manner. CONCLUSION: This study reveals the potent antitumor activity of BVD-523 against thyroid cancer cells bearing MAPK-activating mutations, offering promise for treating aggressive forms of thyroid cancer.


Subject(s)
Aminopyridines , Cell Proliferation , Pyrroles , Thyroid Neoplasms , Humans , Thyroid Neoplasms/drug therapy , Thyroid Neoplasms/pathology , Thyroid Neoplasms/genetics , Thyroid Neoplasms/metabolism , Cell Proliferation/drug effects , Cell Line, Tumor , Protein Kinase Inhibitors/pharmacology , Pteridines/pharmacology , Proto-Oncogene Proteins B-raf/genetics , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Mitogen-Activated Protein Kinase 3/metabolism , Mitogen-Activated Protein Kinase 3/genetics , Antineoplastic Agents/pharmacology , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 1/genetics , Mitogen-Activated Protein Kinase 1/antagonists & inhibitors , Mutation , MAP Kinase Signaling System/drug effects
15.
Leuk Res ; 140: 107495, 2024 May.
Article in English | MEDLINE | ID: mdl-38599153

ABSTRACT

BACKGROUND: Hairy cell leukemia (HCL) is a rare mature B-cell malignancy that is primarily treated with purine analogues. However, relapse remains a significant challenge, prompting the search for alternative therapies. The BRAF V600E mutation prevalent in HCL patients provides a target for treatment with vemurafenib. PATIENTS AND METHODS: This multicenter retrospective study included nine patients with relapsed/refractory (R/R) HCL from six different centers. Patient data included demographics, prior treatments, clinical outcomes, and adverse events. RESULTS: Patients received different treatment regimens between centers, including vemurafenib alone or in combination with rituximab. Despite the differences in protocols, all patients achieved at least a partial response, with seven patients achieving a complete response. Adverse events were generally mild with manageable side effects. The absence of myelotoxic effects and manageable side effects make BRAF inhibitors attractive, especially for patients ineligible for purine analogues or those with severe neutropenia. CONCLUSION: Single agent vemurafenib or in combination with rituximab appears to be a promising therapeutic option for R/R HCL. Further research is needed to establish standardized treatment protocols and to investigate long-term outcomes.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols , Leukemia, Hairy Cell , Rituximab , Vemurafenib , Humans , Leukemia, Hairy Cell/drug therapy , Leukemia, Hairy Cell/pathology , Vemurafenib/administration & dosage , Vemurafenib/therapeutic use , Vemurafenib/adverse effects , Rituximab/administration & dosage , Rituximab/therapeutic use , Rituximab/adverse effects , Male , Middle Aged , Female , Retrospective Studies , Aged , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Adult , Proto-Oncogene Proteins B-raf/genetics , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Neoplasm Recurrence, Local/drug therapy , Neoplasm Recurrence, Local/pathology , Treatment Outcome , Aged, 80 and over , Drug Resistance, Neoplasm
16.
Br J Haematol ; 204(5): 1882-1887, 2024 May.
Article in English | MEDLINE | ID: mdl-38501390

ABSTRACT

Optimal therapeutic approaches for advanced Langerhans cell histiocytosis (LCH) are not known. We assessed the safety and efficacy of combined chemotherapy with MAPK pathway inhibition in 10 patients with refractory systemic disease and/or LCH-associated neurodegeneration. Overall response rate was 9/10 (90%) for the entire cohort: 5/5 (100%) for patients with systemic disease and 6/7 (86%) for patients with central nervous system disease. BRAFV600E+ peripheral blood fraction decreased in 5/6 (83%). Toxicities included fever, skin rash, myalgias, neuropathy, cytopenias and hypocalcaemia. Prospective trials are required to optimize combination strategies, determine potential to achieve cure and compare outcomes to chemotherapy or MAPK inhibitor monotherapy.


Subject(s)
Histiocytosis, Langerhans-Cell , Humans , Histiocytosis, Langerhans-Cell/drug therapy , Male , Female , Adult , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Proto-Oncogene Proteins B-raf/genetics , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Middle Aged , MAP Kinase Signaling System/drug effects , Adolescent , Protein Kinase Inhibitors/therapeutic use , Protein Kinase Inhibitors/adverse effects , Protein Kinase Inhibitors/administration & dosage , Young Adult , Child , Child, Preschool , Recurrence , Treatment Outcome
17.
Cell Death Dis ; 15(3): 183, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38429301

ABSTRACT

Metastatic BRAFV600E colorectal cancer (CRC) carries an extremely poor prognosis and is in urgent need of effective new treatments. While the BRAFV600E inhibitor encorafenib in combination with the EGFR inhibitor cetuximab (Enc+Cet) was recently approved for this indication, overall survival is only increased by 3.6 months and objective responses are observed in only 20% of patients. We have found that a limitation of Enc+Cet treatment is the failure to efficiently induce apoptosis in BRAFV600E CRCs, despite inducing expression of the pro-apoptotic protein BIM and repressing expression of the pro-survival protein MCL-1. Here, we show that BRAFV600E CRCs express high basal levels of the pro-survival proteins MCL-1 and BCL-XL, and that combining encorafenib with a BCL-XL inhibitor significantly enhances apoptosis in BRAFV600E CRC cell lines. This effect was partially dependent on the induction of BIM, as BIM deletion markedly attenuated BRAF plus BCL-XL inhibitor-induced apoptosis. As thrombocytopenia is an established on-target toxicity of BCL-XL inhibition, we also examined the effect of combining encorafenib with the BCL-XL -targeting PROTAC DT2216, and the novel BCL-2/BCL-XL inhibitor dendrimer conjugate AZD0466. Combining encorafenib with DT2216 significantly increased apoptosis induction in vitro, while combining encorafenib with AZD0466 was well tolerated in mice and further reduced growth of BRAFV600E CRC xenografts compared to either agent alone. Collectively, these findings demonstrate that combined BRAF and BCL-XL inhibition significantly enhances apoptosis in pre-clinical models of BRAFV600E CRC and is a combination regimen worthy of clinical investigation to improve outcomes for these patients.


Subject(s)
Antineoplastic Agents , Apoptosis , Carbamates , Colorectal Neoplasms , Protein Kinase Inhibitors , bcl-X Protein , Animals , Humans , Mice , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , bcl-X Protein/antagonists & inhibitors , bcl-X Protein/metabolism , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Myeloid Cell Leukemia Sequence 1 Protein/genetics , Myeloid Cell Leukemia Sequence 1 Protein/metabolism , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/therapeutic use , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Proto-Oncogene Proteins B-raf/genetics , Sulfonamides/pharmacology , Sulfonamides/therapeutic use , Apoptosis/drug effects
18.
Cancer Res ; 84(9): 1379-1381, 2024 May 02.
Article in English | MEDLINE | ID: mdl-38330148

ABSTRACT

Nearly all glioblastoma (GBM) patients relapse following standard treatment and eventually succumb to disease. While large-scale, integrated multiomic studies have tremendously advanced the understanding of primary GBM at the cellular and molecular level, the posttherapeutic trajectory and biological properties of recurrent GBM remain poorly understood. This knowledge gap was addressed in a recent Cancer Cell article in which Kim and colleagues report on a highly integrative proteogenomic analysis performed on 123 matched primary and recurrent GBMs that uncovered a dramatic evolutionary shift from a proliferative state at initial diagnosis to the activation of neuronal and synaptogenic pathways at recurrence following therapy. Neuronal transition was characterized by posttranslational activation of WNT/PCP signaling and BRAF kinase, while many canonical oncogenic pathways, and EGFR in particular, were downregulated. Parallel multiomics analyses of patient-derived xenograft (PDX) models corroborated this evolutionary trajectory, allowing in vivo experiments for translational significance. Notably, targeting BRAF kinase disrupted both the neuronal transition and migration capabilities of recurrent gliomas, which were key characteristics of posttreatment progression. Furthermore, combining BRAF inhibitor vemurafenib with temozolomide prolonged survival in PDX models. Overall, the results reveal novel biological mechanisms of GBM evolution and therapy resistance, and suggest promising therapeutic intervention.


Subject(s)
Brain Neoplasms , Glioblastoma , Proteogenomics , Humans , Glioblastoma/genetics , Glioblastoma/pathology , Glioblastoma/drug therapy , Glioblastoma/metabolism , Proteogenomics/methods , Brain Neoplasms/genetics , Brain Neoplasms/drug therapy , Brain Neoplasms/pathology , Brain Neoplasms/metabolism , Animals , Proto-Oncogene Proteins B-raf/genetics , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Proto-Oncogene Proteins B-raf/metabolism , Neoplasm Recurrence, Local/pathology , Neoplasm Recurrence, Local/genetics , Neoplasm Recurrence, Local/drug therapy , Mice , Temozolomide/pharmacology
19.
Am J Clin Dermatol ; 25(3): 407-419, 2024 May.
Article in English | MEDLINE | ID: mdl-38329690

ABSTRACT

There have been many recent advances in melanoma therapy. While 50% of melanomas have a BRAF mutation and are a target for BRAF inhibitors, the remaining 50% are BRAF wild-type. Immune checkpoint inhibitors targeting PD-1, cytotoxic T-lymphocyte-associated protein 4 (CTLA4) and lymphocyte activated gene-3 (Lag-3) are all approved for the treatment of patients with advanced BRAF wild-type melanoma; however, treatment of this patient population following initial immune checkpoint blockade is a current therapeutic challenge given the lack of other efficacious options. Here, we briefly review available US FDA-approved therapies for BRAF wild-type melanoma and focus on developing treatment avenues for this heterogeneous group of patients. We review the basics of genomic features of both BRAF mutant and BRAF wild-type melanoma as well as efforts underway to develop new targeted therapies involving the mitogen-activated protein kinase (MAPK) pathway for patients with BRAF wild-type tumors. We then focus on novel immunotherapies, including developing checkpoint inhibitors and agonists, cytokine therapies, oncolytic viruses and tumor-infiltrating lymphocytes, all of which represent potential therapeutic avenues for patients with BRAF wild-type melanoma who progress on currently approved immune checkpoint inhibitors.


Subject(s)
Immune Checkpoint Inhibitors , Melanoma , Mutation , Proto-Oncogene Proteins B-raf , Skin Neoplasms , Humans , Melanoma/therapy , Melanoma/genetics , Melanoma/drug therapy , Melanoma/immunology , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Proto-Oncogene Proteins B-raf/genetics , Skin Neoplasms/therapy , Skin Neoplasms/genetics , Skin Neoplasms/drug therapy , Skin Neoplasms/pathology , Skin Neoplasms/immunology , Immune Checkpoint Inhibitors/therapeutic use , Immune Checkpoint Inhibitors/pharmacology , Molecular Targeted Therapy/methods , Immunotherapy/methods , Lymphocytes, Tumor-Infiltrating/immunology , Lymphocytes, Tumor-Infiltrating/drug effects , Oncolytic Virotherapy/methods
20.
Am J Clin Dermatol ; 25(3): 421-434, 2024 May.
Article in English | MEDLINE | ID: mdl-38409643

ABSTRACT

With the development of effective BRAF-targeted and immune-checkpoint immunotherapies for metastatic melanoma, clinical trials are moving these treatments into earlier adjuvant and perioperative settings. BRAF-targeted therapy is a standard of care in resected stage III-IV melanoma, while anti-programmed death-1 (PD1) immunotherapy is now a standard of care option in resected stage IIB through IV disease. With both modalities, recurrence-free survival and distant-metastasis-free survival are improved by a relative 35-50%, yet no improvement in overall survival has been demonstrated. Neoadjuvant anti-PD1 therapy improves event-free survival by approximately an absolute 23%, although improvements in overall survival have yet to be demonstrated. Understanding which patients are most likely to recur and which are most likely to benefit from treatment is now the highest priority question in the field. Biomarker analyses, such as gene expression profiling of the primary lesion and circulating DNA, are preliminarily exciting as potential biomarkers, though each has drawbacks. As in the setting of metastatic disease, markers that inform positive outcomes include interferon-γ gene expression, PD-L1, and high tumor mutational burden, while negative predictors of outcome include circulating factors such as lactate dehydrogenase, interleukin-8, and C-reactive protein. Integrating and validating these markers into clinically relevant models is thus a high priority. Melanoma therapeutics continues to advance with combination adjuvant approaches now investigating anti-PD1 with lymphocyte activation gene 3 (LAG3), T-cell immunoreceptor with Ig and ITIM domains (TIGIT), and individualized neoantigen therapies. How this progress will be integrated into the management of a unique patient to reduce recurrence, limit toxicity, and avoid over-treatment will dominate clinical research and patient care over the next decade.


Subject(s)
Melanoma , Skin Neoplasms , Humans , Melanoma/drug therapy , Melanoma/therapy , Melanoma/pathology , Skin Neoplasms/pathology , Skin Neoplasms/therapy , Skin Neoplasms/drug therapy , Skin Neoplasms/immunology , Immune Checkpoint Inhibitors/therapeutic use , Biomarkers, Tumor , Neoadjuvant Therapy/methods , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Proto-Oncogene Proteins B-raf/genetics , Neoplasm Staging , Neoplasm Recurrence, Local/prevention & control
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